溶蚀混凝土力学性能退化的试验研究

发布时间：2018-03-11 08:18

本文选题：溶蚀混凝土　切入点：溶蚀机理　出处：《浙江工业大学》2016年硕士论文　论文类型：学位论文

【摘要】：通过试验主要研究了不同配合比混凝土力学性能随溶蚀时间的演化规律。在试验过程中,将溶蚀深度、劈拉强度、抗压强度、弹性模量和饱和面干吸水率作为溶蚀混凝土的评价指标,基于试验结果,分析了水灰比和骨料体积含量对溶蚀混凝土力学性能的影响。通过研究得到以下主要结论:(1)酚酞指示剂能很好地表征混凝土的溶蚀深度,溶蚀深度与溶蚀时间的平方根成正比。(2)混凝土的饱和面干吸水率随着溶蚀时间不断增加,对于给定的骨料体积含量和溶蚀时间,水灰比越大,饱和面干吸水率越大。(3)混凝土弹性模量、抗压强度和劈拉强度均随着溶蚀时间的增大而减小,水灰比和骨料体积率对它们的减小速率有较大影响,与弹性模量相比,劈拉强度对于溶蚀的影响更敏感。(4)溶蚀损伤系数与混凝土的弹性模量、抗压强度和劈裂抗拉强度线性相关。介绍了溶蚀混凝土抗压强度预测模型,通过与试验结果比较,验证了该模型的有效性。(5)采用压汞法对不用溶蚀时间的水泥石进行微观分析,结果表明,随着溶蚀的进行,水泥石的密实度不断降低,从而从微观上解释了混凝土性能的退化机理。介绍了溶蚀水泥石孔隙率模型,通过与试验结果比较,验证了该模型的有效性。
[Abstract]:The evolution law of mechanical properties of concrete with different mix ratio with corrosion time was studied. In the process of the test, the corrosion depth, splitting tensile strength, compressive strength were studied. The modulus of elasticity and the dry water absorption of saturated surface are used as evaluation indexes of corroded concrete, based on the test results, The effects of water / cement ratio and aggregate volume content on the mechanical properties of corroded concrete are analyzed. The following main conclusions are obtained: 1) phenolphthalein indicator can well characterize the corrosion depth of concrete. The dry water absorption of the saturated surface of concrete increases with the corrosion time, and the water / cement ratio increases for the given aggregate volume content and dissolution time. The larger the dry water absorption ratio of saturated surface is, the greater the elastic modulus, compressive strength and splitting tensile strength of concrete decrease with the increase of corrosion time. The ratio of water to cement and the volume ratio of aggregate have great influence on the decreasing rate of concrete, compared with the elastic modulus, the ratio of water to cement and the volume ratio of aggregate have great influence on the decreasing rate of concrete. The effect of splitting tensile strength on dissolution is more sensitive. 4) the corrosion damage coefficient is linearly related to the elastic modulus, compressive strength and splitting tensile strength of concrete. The prediction model of compressive strength of corroded concrete is introduced, and the results are compared with the experimental results. The validity of the model is verified. (5) the microcosmic analysis of cement stone without corrosion time is carried out by mercury injection method. The results show that the compactness of cement stone decreases with the corrosion. Therefore, the degradation mechanism of concrete performance is explained microscopically, and the porosity model of corroded cement stone is introduced. The validity of the model is verified by comparing with the experimental results.
【学位授予单位】：浙江工业大学
【学位级别】：硕士
【学位授予年份】：2016
【分类号】：TU528

【参考文献】